/***************************************************************************************
 * SAGE - Scalable Adaptive Graphics Environment
 *
 * Module:  sageCircBuf.h
 * Author : Byungil Jeong
 *
 *   Description: This is the header file for the circular buffer of sage pixel blocks
 *
 *   Notes   :   This class is supposed to provide the common buffers for holding 
 *         the pixel blocks. It also takes care of the reading and writing of pixel blocks 
 *         in a circular fashion. The member functions will be able to provide a complete 
 *         interface to handling these buffers. 
 *         
 *         The algo is that the buffers are writen to and read from in the same direction 
 *         [0 to n and then back to 0]
 *         
 *         
 * Copyright (C) 2004 Electronic Visualization Laboratory,
 * University of Illinois at Chicago
 *
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following disclaimer
 *    in the documentation and/or other materials provided with the distribution.
 *  * Neither the name of the University of Illinois at Chicago nor
 *    the names of its contributors may be used to endorse or promote
 *    products derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Direct questions, comments etc about SAGE to bijeong@evl.uic.edu or 
 * http://www.evl.uic.edu/cavern/forum/
 *
*****************************************************************************************/


#ifndef _SAGECIRCBUF_H
#define _SAGECIRCBUF_H

#include "sageBase.h"

#ifdef BRIDGE_DEBUG_
   #define READER_OFFSET 1
#else
   #define READER_OFFSET 0
#endif

class readerInfo {
public:
   int readIdx;
   bool empty;
   
   readerInfo() : readIdx(0), empty(true) {}
};

class sageCircBuf {
private:
   int readIdx;
   int writeIdx;
   int noOfBlocks;   
   sageBlock *blockArray;   
   std::vector<readerInfo> readerList;
      
   pthread_mutex_t *bufLock;
   pthread_cond_t *notFull;
   pthread_cond_t *notEmpty;
   
   bool full, empty;
   int pixelBlockWidth, pixelBlockHeight, bytesPerPixel;
      
public:
   sageCircBuf() : noOfBlocks(0), full(false), empty(true), 
      pixelBlockWidth(64), pixelBlockHeight(64), bytesPerPixel(3) {}
   int init(int blockNum);   
   
   sageBlock* getNextWriteBlock();    // Returns the next available sage block to write into
   // and advances the index. If no block is available, 
   // this function is blocked until a buffer is read and 
   // becomes available. 
   
   int updateReadIdx(int id);
   int updateReadIdx();
   int updateReadIdx(int id, int bufferMode);
   int updateWriteIdx();
   int distToWriteIdx(int ridx);

   sageBlock* readBlock();
   sageBlock* readBlock(int frameNum);
   sageBlock* readBlock(int id, bool blocking);
   void storeBlockConfig(sageBlock *block);

   int addReader();
   int removeReader(int readerID);
   ~sageCircBuf();
};

#endif
